#include "robust_arithmetic.h"
struct point
{
	double x;
	double y;
	point(double const x, double const y):
		x(x),
		y(y)
	{}
};

int robust_turn(point const a1, point const a2, point const b);
bool is_intersect(point const a1, point const a2, point const b1, point const b2);